1. Field of the Invention
The invention relates to an aligning apparatus for printing units of printing presses.
2. Description of the Related Art
It is known to erect printing units with the aid of at least four adjustable machine feet, what are known as fixators. These machine feet permit setting of the height. Devices which additionally aid the aligning of the printing units in a line are also known.
When printing units are erected on at least four feet, even the smallest height differences of the feet create stresses and distortion in the printing unit, i.e. the two printing-unit walls are displaced with respect to one another. Here, at least two feet are fitted to each of the two printing-unit walls. Each pair of feet exerts a turning moment on the associated wall in the process. Accordingly, numerous adjusting and aligning operations are required in order to erect a previously installed printing unit at a new location, so as to avoid damaging the printing unit as a result of stresses or distortion. It is also known that these aligning operations have to be repeated in order to counteract building movements.
It is an object of the invention to make a simply constructed apparatus for erecting printing units possible, which, moreover, avoids damage as a result of stresses or distortion.
The printing unit has a torsionally rigid base frame and is erected on three points instead of on four, with the aid of adjusting units known per se, what are known as fixators. This erecting process is statically determined and also customary in the case of other machines. No moments can be exerted on the printing-unit frame as a result of this erecting process. The installation state and therefore also the installation accuracy are preserved even after the printing unit is moved. Re-erecting the unit at the customer after transport is simplified and thus substantially accelerated.
It is important that the alignment procedure during erection is simplified and accelerated using the aligning apparatus. A further advantage is that setting phenomena cannot be stressed and distorted again after the printing unit has been aligned.
A substantial advantage of the aligning apparatus is that the vertical adjusting screws, which are arranged on the printing unit, have spherically configured ends, by which they engage in a recess on the positionable plate and are supported there. It is important that the spherical end is mounted in the recess, which is designed as a locating fit, so as to twist or rotate and is completely supported in the recess by means of its spherical surface, so that a short force flow is produced and the rigidity of the entire aligning apparatus is increased. The force, which is transmitted from the adjusting screw to the plate and results from the high mass of the printing unit, can flow in an optimum manner from the adjusting screw to the plate as a result of the configuration as a locating fit, the adjusting screw and the plate representing an xe2x80x9cunreleasablexe2x80x9d connection as a result of the pressure.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.